Generally, in boiling food in a cooking pan, the pan continues to be heated over the fire even after the contents of the pan become boiled so as to ensure that the food in the pan is sufficiently soft.
It has been found, however, that most foods do not need to be cooked at a temperature of 100.degree. C. For example, potatoes and taros can be adequately boiled at temperatures of 80.degree. C. to 90.degree. C., and when meat is boiled or cooked at temperatures of not less than 80. degree. C., the protein thereof is completely denatured. Thus, it has become clear that it is not necessary to continue to heat most of foods in the pan after the food reaches 100.degree. C. and begins to be boiled.
Basically, in cooking foods, it is only necessary for most foods to be maintained at suitable temperatures, for example of 80.degree. to 90.degree. C. for a predetermined time period, for example, of 0.3 to 1 hour. Thus, generally, although energy need to be produced to initially heat the food in the pan up to a predetermined temperature, it is not necessary to continue to heat the foods and keep the food boiling except for the purpose of evaporating water, boiling down of the contents, or the like.
In addition, as a result of various investigations, it has been almost confirmed that seasoning, in other words, the permeation of impregnation of the initially added flavorings into the foods is caused by the difference of the osmotic pressure of the water in the foods or between the soup and foods for reasons of the temperature gradients in the foods occurred at the time of temperature reduction after heating or raising the temperature thereof. Thus, it is important to reduce the temperature not abruptly but smoothly and slowly so as to season the boiled food effectively. In the case of quick reduction of the temperature, the gradient of the osmotic pressure of water in the foods becomes great and the inner pressure of the foods becomes lower than that of the outside thereof. For this reason, the structure of the foods is broken and the contraction of the foods occurs.
Furthermore, it is important not to overheat the foods so as to leave the nutrition values of the respective foods and the “flavor” which is the main elements of tastes of the respective foods after cooking. This applies to the prevention of boil crumbling.
From these findings, it became apparent that, if the temperature reducing process of the foods is rendered slow by extremely preventing the scattering or radiation of the remained heat after performing necessary heating for denaturization of the respective foods, total amounts of heat and adding amounts of water used for cooking are greatly reduced and the foods sufficiently seasoned are obtained without losing their nutrition values, their flavorings, and their original shapes.
Furthermore, one of the daily problems at homes or restaurants about cooking is burning food on the stove which can be caused by forgetting or leaving the food on the stove for a long time which results in burning the food and/or boiling over. This problem knows no young or old, and it can happen to anybody who is cooking, which not only causes pecuniary problems, but also creates the problem of washing the dishes and wasted time, and above all the stench of the burnt food can cause fire. The present invention as described below would overcome all these problems.
The present invention discloses a cooking utensil, which prevents food material from burning and boiling over, and furthermore keeps warm the food material.
The present invention discloses a device not needing electric power or battery. The present invention discloses a device, which is able to cook the food with all kinds of flames or generated heat. Furthermore, the present invention discloses a device that the food therein will not be burned even after several hours of cooking.